The present invention relates to the field of carpet manufacture, and more particularly to methods and apparatus for sculpting patterns in carpet pile.
As has been recognized in the past, designers and artisans have employed various design treatments with respect to carpeting used on both floors and walls. In particular, decorative designs have been sculpted in the carpet pile using hand-held electric or air powered carpet shears or clippers. In the past, to cut decorative designs in carpet pile, it had been suggested to use templates, to pre-mark the carpet and manually cut a pattern in the pile and to use automated, computer controlled cutting tables. Since sculptured effects can involve complex, intricate decorative designs, computer controlled equipment is preferred, not only for purposes of reliability and repeatability, but also to reduce the cost of having a highly skilled artisan engage in such a time consuming task.
One such computer controlled device, disclosed in U.S. Pat. No. 4,793,033xe2x80x94Schneider, et al. and incorporated herein by reference, includes a carriage mechanism adapted to move a clipping mechanism in two dimensions, i.e., to move the clipping mechanism in X and Y directions. This movement is said to be controlled by a computer having a memory into which desired patterns have been stored. In particular, the carriage mechanism includes a table on which a first pulley system moves a wheeled gantry-like structure in one direction and on which a second pulley system located on the gantry moves a wheeled platform in a second perpendicular direction. The clipping mechanism is said to be attached to the platform via a manually adjustable tripod mount which is said to permit variation of the angular orientation of the clipping mechanism. It is asserted that other disclosed mechanisms can move the clipping mechanism vertically as well as rotationally.
Unfortunately, such a computer controlled device suffers from several problems. First, because the clipping mechanism is moved via a tripod mount, setting or making changes to the angular orientation of the clipping blades will result in a relocation of the leading edge or leading prongs, i.e., the beginning cutting point will be offset from the pivot point in the mount. Since the angular setting or adjustment is manually achieved, it will be necessary, if even possible, to align/calibrate or re-align/calibrate the computer program and the clipper blades after each manual adjustment to allow for the relocation of the leading edge, so that the clipping blades cut in the exact locations specified by the computer. Second, because the device is automated, the clipping blades will be moving relative to one another for extended periods of time. The friction forces generated during the clipping operation will lead to elevated temperatures of the clipping blades. It has been found that such elevated temperatures cause the clipping blades to become dull faster, requiring replacement, thereby adding to the cost of operations. Although Schneider et al. suggests providing a lubricant drip to the blades and a vacuum operation, these features are not believed sufficient to maintain acceptable blade temperature for extended periods.
In addition, the Schneider et al. device does not account for pile deflection. It has been found that when a clipping mechanism is brought into contact with the carpet pile, the bottom of the clipping mechanism tends to compress or deflect the pile directly under the clipping blades. This deflection or compression can cause unwanted imperfections, i.e., tufts. Moreover, for direction changes where a clipping blade would be moved away from and then onto the pile, the tuft imperfection itself can be deflected or compressed, making matters worse. The presence of such tuft imperfections will require a manual finishing operation in order to achieve the desired appearance. Moreover, carpet pile over an extended area can have a random angle, bias or direction. During manual sculpting operations, the artisan will frequently brush the pile with a hand in order to orient the pile in a desired direction before clipping. The Schneider et al. device makes no mention, nor does it suggest a solution to this problem.
Although not resolving any of the above described problems, U.S. Pat. No. 5,285,558xe2x80x94Carder et al., incorporated herein by reference, discloses a hand operated device, containing a clipping mechanism, which is moved manually to trim carpet pile or to bevel the edge of the pile. In relation to the beveling operation, Carder et al. disclose a mounting bracket which permits pivoting of the clipping mechanism. Unfortunately, this pivoting movement also results in a relocation of the leading edge or leading prongs.
Additionally, the assignee of the present invention sells a carpet design and cutting system which incorporates a computer controlled cutting table. In this device, a desired pattern is entered into the computer and the computer causes the cutting table to cut the desired design into a piece of carpet held in place by a vacuum. Since this pattern cutting device has not heretofore been adapted to sculpt carpet, it too has not solved any of the above described problems.
Consequently, a need still exists for a carpet clipping device which controls clipping blade temperature during extended clipping operation, provides accurate angled orientation of the clipping blades, accounts for pile compression/deflection whenever the clipping blade is moved against the pile and which accounts for random pile direction.
It has been noted that many of the above described problems can be resolved and other advantages achieved in a carpet pile cutter which includes a clipper having a driver, a reciprocating blade and a fixed blade. The fixed blade and the reciprocating blade define an area there between. The fixed blade has a bore passing through the blade and into the area. A fluid supply, connected to the bore, supplies fluid through the fixed blade and into the area. A manifold, attached to the fixed blade, can be used to pass fluid through the fixed blade into the chamber. In such an embodiment, the manifold includes a passage communicating with the bore and the fluid supply.
In another embodiment, an orientation mechanism is used to orient the carpet clipping head. In this embodiment, the orientation mechanism includes a base bracket and a pivot bracket. The pivot bracket is pivotally attached to the base bracket at a pivot point. The carpet clipping head is attached to the pivot bracket so that movement of the pivot bracket causes the carpet clipping head to pivot about the lead prong. In such an embodiment, it is preferred for the base bracket to have a first pivot bore and for the pivot bracket to have a second pivot bore. It is especially preferred for the first and second pivot bores and the lead prong to lie substantially along a pivot axis. It is also preferred for the base bracket to include a threaded receptacle and for the pivot bracket to include an arcuate slot oriented to pass proximate the receptacle. In such an embodiment, a locking bolt is passed through the slot to engaging the receptacle and hold the pivot bracket in place by frictionally locking the pivot bracket to the base bracket.
In yet another embodiment, the carpet trimmer is attached to a computer controlled carrier platform. In such an embodiment, the carpet trimmer is spaced from the point at which the clipping blade contacts the pile before cutting the pile.
In a still further embodiment, a pile orientation member is provided for orienting pile in the path of the clipper head so that the pile is oriented in a plane substantially perpendicular to the cutting plane. In such an embodiment, the pile orientation member includes a friction engaging member for frictionally engaging and orienting the pile. The friction engaging member can take many forms such as a roller or belt arrangement rotating in a direction which urges the pile toward the clipper head.